Bug 1023035 - Improve checking for whether we are on the main thread when triggering malloc GCs, r=billm.

js/src/jsgc.cpp

@@ -2145,12 +2145,17 @@ GCRuntime::triggerGC(JS::gcreason::Reason reason)
         return true;
     }
 
+    /*
+     * Don't trigger GCs if this is being called off the main thread from
+     * onTooMuchMalloc().
+     */
+    if (!CurrentThreadCanAccessRuntime(rt))
+        return false;
+
     /* Don't trigger GCs when allocating under the interrupt callback lock. */
     if (rt->currentThreadOwnsInterruptLock())
         return false;
 
-    JS_ASSERT(CurrentThreadCanAccessRuntime(rt));
-
     /* GC is already running. */
     if (rt->isHeapCollecting())
         return false;

js/src/vm/Runtime.cpp

@@ -710,8 +710,6 @@ JSRuntime::updateMallocCounter(JS::Zone *zone, size_t nbytes)
 JS_FRIEND_API(void)
 JSRuntime::onTooMuchMalloc()
 {
-    if (!CurrentThreadCanAccessRuntime(this))
-        return;
     gc.onTooMuchMalloc();
 }